According to Maxwell electromagnetic field theory and magnetic vector potential integral equation,a mathematical model of LMF(Level Magnetic Field)for EMBR(Electromagnetic brake)was proposed,and the reliable software ...According to Maxwell electromagnetic field theory and magnetic vector potential integral equation,a mathematical model of LMF(Level Magnetic Field)for EMBR(Electromagnetic brake)was proposed,and the reliable software for LMF calculation was developed.The distribution of magnetic flux density given by numerical simulation shows that the magnetic flux density is greater in the magnet and magnetic leakage is observed in the gap.The magnetic flux density is uniform in horizontal plane and a peak is observed in vertical plane.Furthermore,the effects of electromagnetic and structural parameters on magnetic flux density were discussed.The relationship between magnetic flux,electromagnetic parameters and structural parameters is obtained by dimensional analysis,simulation experiment and least square method.展开更多
The Xuhe mafic rocks, located in Ziyang county of Shaanxi Province, are dominated by diabase-porphyrite, gabbro-diabase, diabase, and pyroxene diorite. Primitive mantle-normalized multi-element patterns show that, the...The Xuhe mafic rocks, located in Ziyang county of Shaanxi Province, are dominated by diabase-porphyrite, gabbro-diabase, diabase, and pyroxene diorite. Primitive mantle-normalized multi-element patterns show that, the Xuhe marie rocks are enriched in large ion lithophile elements （LITE）, such as Ba and Pb, depleted in K and Sr for basic rocks, and are depleted in Sr, P and Ti for pyroxene diorite. Chondrite-normalized REE patterns display LREE enrichment （LaN/YbN = 9.34- 13.99） and have normalized patterns for trace element and REE similar to that of typical OIB. Detailed SIMS zircon U-Pb dating yields emplacement ages of 438.4 ± 3.1 Ma for Xuhe mafic rocks. The relatively low MgO （basic rock： 3.11-7.21 wt%; pyroxene diorite： 0.89-1.21 wt% ） and Mg# （0.20- 0.49） for Xuhe mafic rocks suggest that they were possibly originated from an extremely evolved magma. The rising parental mafic magmas underwent pyroxene and plagioclase fractionation. Crustal contamination of pyroxene diorite before emplacement occurred at a higher crustal level compared to other lithology in Xuhe mafic rocks. The degree of partial melt was low （5%-10%） and in garnetspinel transition facies. Sr-Nd isotope of pyroxene diorite and enrichment mantle characteristics for Xuhe mafic rocks suggest that mafic rocks in the North Daba Mountains were derived from a mixture of HIMU, EMII and small amount of EMI components. Furthermore, this study discusses mantle geodynamic significance of Xuhe mafic rocks in the Silurian, which indicates subduction and uplift of magma caused back-arc extension.展开更多
Abstract Spreading of nanofluids on solid substrate was studied via molecular dynamics simulations. Simulation models for two immiscible fluids （oil and water based nanofiuids） confined in a slit between two planar ...Abstract Spreading of nanofluids on solid substrate was studied via molecular dynamics simulations. Simulation models for two immiscible fluids （oil and water based nanofiuids） confined in a slit between two planar solid walls were set up. The influence of the volume concentration of the nanoparticles on the three-phase contact line motion was investigated. We found that the larger volume concentration results in more visible nanoparticle adsorption on solid surface. This effect further induces an advancing displacement of the contact line compared with the meniscus profiles in low concentration case and that with the absence of nanoparticles. These findings are consistent with the previous experimental and theoretical results and provide the atomic-scale understanding on nanofluid spreading.展开更多
基金Item Sponsored by National Key Fundamental Research Development Project of China(G1998061510)
文摘According to Maxwell electromagnetic field theory and magnetic vector potential integral equation,a mathematical model of LMF(Level Magnetic Field)for EMBR(Electromagnetic brake)was proposed,and the reliable software for LMF calculation was developed.The distribution of magnetic flux density given by numerical simulation shows that the magnetic flux density is greater in the magnet and magnetic leakage is observed in the gap.The magnetic flux density is uniform in horizontal plane and a peak is observed in vertical plane.Furthermore,the effects of electromagnetic and structural parameters on magnetic flux density were discussed.The relationship between magnetic flux,electromagnetic parameters and structural parameters is obtained by dimensional analysis,simulation experiment and least square method.
基金granted by the foundamental research funds for central public welfare research institutes(Grant No.K1313)the Natural Sciences Foundation of China(Grant No.41302080)China State Geological Investigation Program(Grant No.1212011121091,12120114009401)
文摘The Xuhe mafic rocks, located in Ziyang county of Shaanxi Province, are dominated by diabase-porphyrite, gabbro-diabase, diabase, and pyroxene diorite. Primitive mantle-normalized multi-element patterns show that, the Xuhe marie rocks are enriched in large ion lithophile elements （LITE）, such as Ba and Pb, depleted in K and Sr for basic rocks, and are depleted in Sr, P and Ti for pyroxene diorite. Chondrite-normalized REE patterns display LREE enrichment （LaN/YbN = 9.34- 13.99） and have normalized patterns for trace element and REE similar to that of typical OIB. Detailed SIMS zircon U-Pb dating yields emplacement ages of 438.4 ± 3.1 Ma for Xuhe mafic rocks. The relatively low MgO （basic rock： 3.11-7.21 wt%; pyroxene diorite： 0.89-1.21 wt% ） and Mg# （0.20- 0.49） for Xuhe mafic rocks suggest that they were possibly originated from an extremely evolved magma. The rising parental mafic magmas underwent pyroxene and plagioclase fractionation. Crustal contamination of pyroxene diorite before emplacement occurred at a higher crustal level compared to other lithology in Xuhe mafic rocks. The degree of partial melt was low （5%-10%） and in garnetspinel transition facies. Sr-Nd isotope of pyroxene diorite and enrichment mantle characteristics for Xuhe mafic rocks suggest that mafic rocks in the North Daba Mountains were derived from a mixture of HIMU, EMII and small amount of EMI components. Furthermore, this study discusses mantle geodynamic significance of Xuhe mafic rocks in the Silurian, which indicates subduction and uplift of magma caused back-arc extension.
基金supported by the National Natural Science Foundation of China(11172289,U1262103,and 11302218)Anhui Provincial Natural Science Foundation(1308085QA10)+1 种基金China Postdoctoral Science Foundation(2012M521243)the Fundamental Research Funds for the Central Universities of China(WK2090050022 and WK20900050027)
文摘Abstract Spreading of nanofluids on solid substrate was studied via molecular dynamics simulations. Simulation models for two immiscible fluids （oil and water based nanofiuids） confined in a slit between two planar solid walls were set up. The influence of the volume concentration of the nanoparticles on the three-phase contact line motion was investigated. We found that the larger volume concentration results in more visible nanoparticle adsorption on solid surface. This effect further induces an advancing displacement of the contact line compared with the meniscus profiles in low concentration case and that with the absence of nanoparticles. These findings are consistent with the previous experimental and theoretical results and provide the atomic-scale understanding on nanofluid spreading.
